Wisconsin Gov. Scott Walker talks about the release of thousands of emails and other documents collected during a criminal investigation of a former aide on Wednesday.

MADISON, Wis. — Former aides to Wisconsin Gov. Scott Walker when he served as a county executive routinely mixed county and campaign business, copying in the candidate on many messages even after he told them to stop, according to thousands of emails and other court documents released Wednesday.

Walker, who faces re-election this year and is considering a run for president in 2016, was not charged with any wrongdoing in the investigation that closed last year with convictions against six of his former aides and associates.

Democrats pounced on the latest records dump, hoping Walker would be sunk by the investigation that has shadowed him for years and was used unsuccessfully against him in his 2010 run for governor and 2012 recall.

Democratic National Committee Chair Debbie Wasserman Schultz of Florida, in a conference call with reporters, attempted to link the Walker investigation with scandals that have hit Republican New Jersey Gov. Chris Christie and Virginia Gov. Bob McDonnell.

“If these ethical scandals are the way (Republican governors) lead, that’s got to be something we all make sure voters pay attention to,” Schultz said.

Walker said his political opponents would spin the records to their advantage, but there were no surprises in them.

“These people are naysayers who want things bad to happen in Wisconsin, so they are going to be circling again today,” Walker said. “It’s exactly what’s wrong with the political process that they’re hoping for something bad to happen in Wisconsin. It’s not. They’re going to do what they’ve done in the past which is over-hype things. And politically they’re going to be disappointed.”

So far, Walker has escaped being tainted by the probe. A second secret investigation that developed during the earlier one is ongoing and reportedly looking into fundraising and other activities by Walker’s campaign and conservative groups.

The roughly 28,000 pages of emails and other documents were collected during the investigation into Kelly Rindfleisch, who served as Walker’s deputy chief of staff in his Milwaukee County executive’s office in 2010. She was convicted in 2012 of misconduct in office, a felony, for doing campaign work for Republican lieutenant governor candidate Brett Davis on government time.

Rindfleisch, who is appealing her conviction, was sentenced to six months in jail and three years of probation.

Court records previously released showed that Walker’s aides in the county office set up a secret wireless router in his office to email one another about both county and campaign business.

In one email, sent March 22, 2010, Walker’s administration director Cynthia Archer told Rindfleisch she could consider herself part of the “inner circle,” adding that she frequently uses her private email account to communicate with Walker.

Two months later, Walker’s constituent services manager, Darlene Wink, resigned after a newspaper reported she was posting pro-Walker comments on various websites while at work.

“We cannot afford another story like this one,” Walker wrote to his aides on May 14, 2010. “No one can give them any reason to do another story. That means no laptops, no websites, no time away during the work day, etc.”

Walker told The Associated Press in November 2012 that he had built a firewall to ensure county workers were not ordered to do campaign work while on county time.